Multitenant Database Placement with a Cost Based Query Scheduler

Abstract

Systems and methods are disclosed for placing tenants in a cloud based database server, by estimating with a processor a cost of placing a set of tenants on a server using a simulator; estimating a relative importance of different tenant's queries; and selecting an optimal server for each tenant based with a cost-based schedular to maximize profit using the simulator.

What is claimed is: 
     
         1 . A method for placing tenants in a cloud based database server, comprising:
 estimating with a processor a cost of placing a set of tenants on a server using a simulator;   estimating a relative importance of different tenant's queries; and   selecting an optimal server for each tenant based with a cost-based schedular to maximize profit using the simulator.   
     
     
         2 . The method of  claim 1 , comprising receiving a service level agreement (SLA) for mapping from tenants to servers 
     
     
         3 . The method of  claim 1 , comprising simulating a mixed workload of all tenant's queries with a load. 
     
     
         4 . The method of  claim 1 , comprising determining an average cost per query of a tenant. 
     
     
         5 . The method of  claim 1 , comprising determining an average cost per query of tenant in a mixed workload. 
     
     
         6 . The method of  claim 1 , comprising determining an importance of a tenant based on an average cost per query of a tenant alone and an average cost per query of a tenant in a mixed workload. 
     
     
         7 . The method of  claim 1 , comprising determining an importance of a tenant i at a load x as: 
       
         
           
             
               
                 imp 
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               = 
               
                 
                   
                     
                       cost 
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                       cost 
                       together 
                     
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                 . 
               
             
           
         
       
     
     
         8 . The method of  claim 1 , comprising determining which tenant is more important by integrating a probability density function (PDF) of an aggregate load f(x) of load:
   imp( i )=∫ r   (x) imp( i,x )· f ( x ) dx  
   where r is approximately near one.   
     
     
         9 . The method of  claim 1 , comprising estimating a cost of placing a tenant on a server using a simulator and placing the tenant on the server with the lowest incremental cost after adding the tenant. 
     
     
         10 . The method of  claim 1 , comprising applying a worst fit strategy for tenant placement with an incremental cost-based scheduler (iCBS) and the simulator for cost balancing. 
     
     
         11 . A system for placing tenants in a cloud based database server, comprising:
 estimating with a processor a cost of placing a set of tenants on a server using a simulator;   estimating a relative importance of different tenant's queries; and   selecting an optimal server for each tenant based with a cost-based schedular to maximize profit using the simulator.   
     
     
         12 . The system of  claim 11 , comprising code for receiving a service level agreement (SLA) for mapping from tenants to servers 
     
     
         13 . The system of  claim 11 , comprising code for simulating a mixed workload of all tenant's queries with a load. 
     
     
         14 . The system of  claim 11 , comprising code for determining an average cost per query of a tenant. 
     
     
         15 . The system of  claim 11 , comprising code for determining an average cost per query of tenant in a mixed workload. 
     
     
         16 . The system of  claim 11 , comprising code for determining an importance of a tenant based on an average cost per query of a tenant alone and an average cost per query of a tenant in a mixed workload. 
     
     
         17 . The system of  claim 11 , comprising code for determining an importance of a tenant i at a load x as: 
       
         
           
             
               
                 imp 
                  
                 
                     
                 
                  
                 
                   ( 
                   
                     i 
                     , 
                     x 
                   
                   ) 
                 
               
               = 
               
                 
                   
                     
                       cost 
                       alone 
                     
                      
                     
                       ( 
                       
                         i 
                         , 
                         x 
                       
                       ) 
                     
                   
                   
                     
                       cost 
                       together 
                     
                      
                     
                       ( 
                       
                         i 
                         , 
                         x 
                       
                       ) 
                     
                   
                 
                 . 
               
             
           
         
       
     
     
         18 . The system of  claim 11 , comprising code for determining which tenant is more important by integrating a probability density function (PDF) of an aggregate load f(x) of load:
   imp( i )=∫ r   (x) imp( i,x )· f ( x ) dx  
   
     
     
         19 . The system of  claim 11 , comprising code for estimating a cost of placing a tenant on a server using a simulator and placing the tenant on the server with the lowest incremental cost after adding the tenant. 
     
     
         20 . The system of  claim 11 , comprising code for applying a worst fit strategy for tenant placement with an incremental cost-based scheduler (iCBS) and the simulator for cost balancing.